The present invention relates generally to a superconductive lead assembly for a superconductive device cooled by a cryocooler coldhead, and more particularly to such an assembly which has ceramic superconductive leads resistant to breakage.
Superconducting devices include, but are not limited to, superconducting magnetic-energy storage devices, superconducting rotors, and superconducting magnets. Superconducting magnets include those having ceramic superconductive leads which supply electricity to the superconductive coils which generate uniform and high strength magnetic fields. Superconducting magnets include those used in magnetic resonance imaging (MRI) systems employed in the field of medical diagnostics. Known techniques for cooling a superconductive magnet include those in which the superconductive coil is cooled through solid conduction by a cryocooler coldhead.
Known ceramic superconductive leads include DBCO (Dysprosium Barium Copper Oxide), YBCO (Yttrium Barium Copper Oxide), and BSCCO (Bismuth Strontium Calcium Copper Oxide) superconducting leads having a first end flexibly, dielectrically, and thermally connected to the cryocooler coldhead's first stage (at a temperature of generally 40 Kelvin) and a second end flexibly, dielectrically, and thermally connected to the cryocooler coldhead's second stage (at a temperature of generally 10 Kelvin).
Great care must be exercised when handling ceramic superconductive leads because they are brittle and break easily such as during installation of the leads in the magnet. In addition, superconductive leads installed in a superconductive device are sometimes subject to shock and vibration forces which could lead to breakage. For example, the superconductive leads in an MRI magnet are susceptible to shock and vibration forces during magnet shipping and installation, and the superconductive leads in a naval magnet are susceptible to shock and vibration forces while the magnet is in use during mine-sweeping operations. Known ceramic superconductive lead assemblies offer no protection against breakage due to handling of the lead or due to shock and vibration forces experienced during shipping and installation of the superconductive device containing the lead assemblies. What is needed is a superconductive lead assembly for a superconductive device cooled by a cryocooler coldhead wherein the ceramic superconductive leads are protected against breakage.